Moderators: richierich, ua900, PanAm_DC10, hOMSaR
LH707330 wrote:The 6 individual pods give you more safety from contagious failures at the expense of more wetted surface. Engines in side-by-side pods have experienced contagious failures on Il-62s:
https://en.wikipedia.org/wiki/LOT_Polis ... s_Flight_7
https://en.wikipedia.org/wiki/LOT_Polis ... light_5055
My guess is on the B-47 they figured that the presence of ejection seats and the outer engines on their own pods gave them enough margin in case an inner pair went bust, while the An-225 designers had the two LOT flights fresh in their memories and also wanted more safety margin for cargo and pax operations. There's an early render of the 707 with the double pods as seen on the B-47, evidently Boeing figured the wetted drag penalty was worth the safety gain. Pan Am 843 appears to have vindicated that design decision:
https://en.wikipedia.org/wiki/Pan_Am_Flight_843
kitplane01 wrote:LH707330 wrote:The 6 individual pods give you more safety from contagious failures at the expense of more wetted surface. Engines in side-by-side pods have experienced contagious failures on Il-62s:
https://en.wikipedia.org/wiki/LOT_Polis ... s_Flight_7
https://en.wikipedia.org/wiki/LOT_Polis ... light_5055
My guess is on the B-47 they figured that the presence of ejection seats and the outer engines on their own pods gave them enough margin in case an inner pair went bust, while the An-225 designers had the two LOT flights fresh in their memories and also wanted more safety margin for cargo and pax operations. There's an early render of the 707 with the double pods as seen on the B-47, evidently Boeing figured the wetted drag penalty was worth the safety gain. Pan Am 843 appears to have vindicated that design decision:
https://en.wikipedia.org/wiki/Pan_Am_Flight_843
On the LOT-7 flight, the one engine blowing up took out TWO other engines. That cannot be good. (and the controls to the elevator, which was quite bad.)
On the LOT-5055, the one engine blowing up ALSO took out the controls to the elevator.
Makes me wonder about the Il-62 and it's elevator controls!
Can a 707 maintain altitude with 2 engines one one side and nothing on the other?
Although in the six engine scenario, even losing a pod gives you 4/6 of the total engine, which is enough for any reasonable plane to maintain altitude.